ornithine

American  

[awr-nuh-theen] / ˈɔr nəˌθin /

noun

Biochemistry.

1. an amino acid, H 2 N(CH2 ) 3 CH(NH2 )COOH, obtained by the hydrolysis of arginine and occurring as an intermediate compound in the urea cycle of mammals.

---

ornithine British  

/ ˈɔːnɪˌθiːn /

noun

1. an amino acid produced from arginine by hydrolysis: involved in the formation of urea in the liver; diaminopentanoic acid. Formula: NH 2 (CH 2 ) 3 CHNH 2 COOH

---

ornithine Scientific  

/ ôr′nə-thēn′ /

1. An amino acid not found in proteins, formed by hydrolyzing arginine and important in the formation of urea. Chemical formula: C ₅ H ₁₂ N ₂ O ₂ .

---

Etymology

Origin of ornithine

1880–85; ornith(uric acid) , secreted by birds + -ine ²

Example Sentences

See Examples For:

ornithine

In fact, two amino acids, lysine and ornithine, became more abundant in the gut after infection.

From Science Daily ● Nov. 15, 2024

The enzyme ornithine transcarbamylase catalyzes a key step in the urea cycle and its deficiency can lead to accumulation of toxic levels of ammonia in the body.

From Textbooks ● Jun. 9, 2022

Gelsinger died during a clinical trial to cure ornithine transcarbamylase deficiency, a genetic condition that he suffered from.

From Scientific American ● Feb. 12, 2021

One possible way to explain this is if the core apoptotic machinery prevents ornithine from entering the mitochondrion and instead diverts it towards spermidine production.

From Nature ● Mar. 17, 2020

The precursors are two essential amino acids, argenine and ornithine and certain vitamins such as C and B 6.

From How and When to Be Your Own Doctor by Solomon, Steve